Variable-inductance tuner



Patented Dec. 2, 1924.

IRVIN 0. ANDERSON, OF TRINIDAD, COLORADO.

VARIABLE-INDUCTANCE TUNER.

Application led December 7, 1922.

To all whom it may concern:

Be it known that l, InvrN O. ANDERSON, a citizen of the UnitedStates, residing at Trinidad, in the county of Las Animas and State of Colorado, have invented certain new and useful Improvements in Variable- Inductance Tuners, and I do hereby declare the following to be a full. clear, and exact description ofthe invention, such will enable others v skilled in the art to which it appertains tomake and use the same.

The,invention has for'its primary object the provision of a device'forV varying the inductance in a radio transmitter or receiver circuits to change the wave length and allow for `timing, and aimsto provide a device which may be easily constructed and which is compact and which may be readily in stalled and readily adjusted to meet existing conditions and' requirements.

Other obiects and advantages will be apparent 'and"suggest themselves as the nature ofthe. invention is .understood While the drawings Aillustrate an embodiment of the invention it is to be understood that in adapting the same to meet different conditions and requirements, various changes in the form, proportion and minor details of construction may be resorted to without de arting from the nature of the invention.

Feferring to the accompanying drawings forming a part of the application,

Figure 1 is an elevation of a device embodying the invention,

Figure 2 is a section thereof on the line 2 2, of Figure 1.

Figure 3 is an elevation of the rotary member,

Figure 4 is a diagrammatical view of the rotary member and connections,

Figure 5 is a detail view of the separable plate for securing the operating stem to the rotary member,

Figure 6 is a view Similar to Figure 1 of a modification,

Figure 7 is an edge view of the modification,

Figure 8 is a view similar to Figure 3 of the rotary member embodied in the modi tication. and

Figure 9 is a diagrammatic view of the modified form of rotary member and connections associated therewith.

Corresponding and like parts are referred to in the following description and de- Serial No. 605,445.

signated in the several views of the drawings by like reference characters.

The device comprises an outer stationary member and an inner rotary member, each of the members embodying a coil of wire, and the coils of both members may bein series, as indicated in Figure 1, and the detail views thereof are adapted to be independently coupled, as indicated in Figure 6 and the detail views thereof. A vital feature of the structure, however, resides in having both members of flat form-for compactness, cheapness of construction'and ease of installation and' adjustment lwhen tuning. The general outline of themembers is immaterial but it is preferred to have the rotary member of circular form` but'the cuter member may be of rectangular form, as indicated in Figure 1, o`r of circular outline, as indicated in Figure 6. f

Referring to Figure 1 and the detail views thereof, the outer member is designatedby the numeral 1 and comprises two rectangular plates of insulating material disposed in parallel relation and spaced apart a suitable distance, blocks 2 being interposed therebetween and preferably disposed lat Ethe corners whereby to provide ample room for the rotary member. Wire of suitable gage is wound about the member 1 to form a coil 3 and a terminal of such wire is connected to a binding post 4. The other terminal of the wire is connected to a plate 5 secured to a side of the frame comprising the member and provided with a threaded opening 1. The side plates comprising the frame are thin for lightness, compactness and neatness.

The rotary member G is flat and prefer ably of circular outline and is of a size to fit within the member 1 and turn freely. A wire is wound about the rotary member 6 to form a coil 7 and one end of said wire is connected to a plate 8 upon one side of the member 6 and the other end is connected to a plate 9 upon the opposite side of the member. A trunnion screw 10 engages the threaded opening in plate 5 and also engages an opening in plate 8 and a wire 11 connects the elements 5 to a binding post 12. A stem 18 connects the element 9 with a plate 15 to which an end of the wire forming the coil 3 is connected, with the result that the two coils 3 and 7 are connected in series, having the two binding posts 4 and 12) whereby to couple the device when operatively positioned in a set. The inner end of the stem 16 is ol noneircular form and tits a socket of corresponding shape formed in a side of the member 6, whereby rotation of the stem 13 in either direction effet-ts a corresponding rotation of the member (3. An annular groove 17 formed adjacent the inner end or" the stem 13 receives the plate l5, whereby the stem is held in position. As shown most clearly in Figure 5, the plate 15 is formed of sections notched in their inner or meeting edges to snugly fit the annular groove 17 of the stem 13 whereby displaceA ment of the latter is prevented after the plate 15 has been made secure to the outer side of the casing comprising the member 1.

In the construction shown in Figure G, the outer member 1a is of circular outline. being otherwise substantially the same in construction as the member 1 and having a wire Wound thereabout to form a coil 3. Binding posts 19 and 20, applied to the frame or casing of the member l, have opposite ends of the Wire forming the coil 3 connected thereto.

The-rotary member 6a is similar to the corresponding member 6 and has a wire wound thereabout to form a coil 7. Plates 21 and 22, attached to opposite sides of the member 6*, have opposite ends of the wire forming the coil 7 connected thereto. A trunnion .screw 23, pivotally connecting the member 6a to the member l, is connected to abindi'ng post 24 Aby means of a wire 25, and a plate 151s electrically connected to the plate 22 by means of a stem 125 and a wire 26 connects said plae to a binding post 27. yl`he pairs l5 and 115 are substantially the saine as corresponding parts shown most clearly` in Figures 4 and lt will thus be understood that the modiiied structure is adapted to have the coils 3 and 7 independentl i connected.

Tlie flat formation of the members is important for simplicity and cheapness of structure7 coii'ipactness and ease of installation selectivity when tuning the transmitter or receiver of :i radio wireless.

What is. claimed is:

In a radio Avariable inductanee, an outer flat member7 an inner flat member rotatable relative to the outer member, inductance coils wound around said members, a trunnion screw mounted in one side of the outer member and in supporting relation with the inner member, a stem mounted in the 0pp0- site side of the outer member and having connection with the inner member to rotate therewith and form a support therefor, and a plate attached to a side of the outer member and engagingr said stem to retain it in given position, said truunion screw and stem operating to electrically connect the wires forming the coils surrounding the two members ln testimony whereof I affix my signature in presence of two Witnesses.

IRVIN O. ANDERSON. lVitnesseS WILLIAM H. HYDE, FRED J. COOK. 

